Rotary fastener

Abstract

A rotary fastener includes a mounting base member including an inner barrel and an outer barrel fixedly fastened together, a fastening device including a spring-loaded pin member inserted through the mounting base member and a head member affixed to the pin member outside the mounting base member, an operating cap member fixedly mounted with the head member and rotatable relative to the mounting base member between an upper-limit position and a lower-limit position to move the pin member in and out of the bottom side of the mounting base member between a locking position and an unlocking position, and a guide track unit for guiding movement of the operating cap member relative to the mounting base member between the upper-limit position and the lower-limit position upon a rotary motion.

What the invention claimed is: 
     
         1 . A rotary fastener installed in a mounting through hole of a first panel member and adapted for detachably locking said first panel member to a locking hole of a second panel member, the rotary fastener comprising:
 a mounting base member comprising an inner barrel and an outer barrel molded on said inner barrel by insert molding, said inner barrel comprising an accommodation chamber defined therein, a top neck located at a top side thereof and upwardly extended out of said outer barrel and a bottom mounting neck located at an opposing bottom side thereof and affixed to said mounting through hole of said first panel member;   a fastening device, said fastening device comprising a head member disposed outside said mounting base member, a pin member having a top end thereof upwardly inserted through said accommodation chamber of said inner barrel of said mounting base member and fixedly connected to said head member and an opposing bottom end thereof terminating in an expanded bottom engagement portion that is adapted for engaging into said locking hole of said second panel member to lock said second panel member to said first panel member, and an elastic member mounted around said pin member and stopped between said expanded bottom engagement portion of said pin member and a part of said inner barrel in said accommodation chamber;   an operating device, said operating device comprising an operating cap member fixedly mounted with said head member of said fastening device and supported on said outer barrel of said mounting base member and rotatable by an external force relative to said outer barrel between a lower-limit position and an upper-limit position to move said pin member between a locking position where said expanded bottom engagement portion of said pin member is engaged into said locking hole of said second panel member to lock said second panel member to said first panel member and an unlocking position where said expanded bottom engagement portion of said pin member is disengaged from said locking hole of said second panel member and received inside said accommodation chamber of said inner barrel for allowing separation between said first panel member and said second panel member; and   a guide track unit located at a bottom side of said operating cap member and a top side of said outer barrel of said mounting base member and adapted for guiding said operating cap member to move relative to said outer barrel of said mounting base member between said upper-limit position and said lower-limit position through a rotary motion.   
     
     
         2 . The rotary fastener as claimed in  claim 1 , wherein said inner barrel comprises an engagement structure extending around the whole area of the periphery thereof for engagement with an inside wall of said outer barrel, said engagement structure comprising a plurality of grooves and ribs alternatively spaced around the periphery of said inner barrel. 
     
     
         3 . The rotary fastener as claimed in  claim 1 , wherein said inner barrel comprises an engagement structure extending around at least one segment of the periphery thereof for engagement with an inside wall of said outer barrel, said engagement structure comprising a plurality of grooves and ribs alternatively spaced around the periphery of said inner barrel. 
     
     
         4 . The rotary fastener as claimed in  claim 1 , wherein said pin member comprises a mounting tip located at the top end thereof; said head member comprises a center mounting hole fixedly fastened to said mounting tip of said pin member, and an engagement wall extending around the periphery thereof; said operating cap member comprises a locating groove located on an inside wall thereof and fixedly fastened to said engagement wall of said head member. 
     
     
         5 . The rotary fastener as claimed in  claim 1 , wherein said guide track unit comprises a plurality of high-position locating surface portions equiangularly spaced on the top side of said outer barrel, a plurality of homing surface portions located at the top side of said outer barrel at a relatively lower elevation than said high-position locating surface portions and respectively spaced between each two adjacent said high-position locating surface portions, and a plurality of positioning surface portions equiangularly spaced on the bottom side of said operating cap member and movable with said operating cap member between said upper-limit position where said positioning surface portions are respectively positioned on said high-position locating surface portions and said lower-limit position where said positioning surface portions are respectively positioned on said homing surface portions. 
     
     
         6 . The rotary fastener as claimed in  claim 5 , wherein the number of said high-position locating surface portions is 2, and these two said high-position locating surface portions are spaced from each other at 180°; the number of said homing surface portions is 2, and these two said homing surface portions are spaced from each other at 180°; the number of said positioning surface portions is 2, and these two said positioning surface portions are spaced from each other at 180°. 
     
     
         7 . The rotary fastener as claimed in  claim 5 , wherein the number of said high-position locating surface portions is 4, and these four said high-position locating surface portions are spaced from each other at 90°; the number of said homing surface portions is 4, and these four said homing surface portions are spaced from each other at 90°; the number of said positioning surface portions is 4, and these four said positioning surface portions are spaced from each other at 90°. 
     
     
         8 . The rotary fastener as claimed in  claim 5 , wherein said guide track unit further comprises a plurality of first sloping guide paths located at the top side of said outer barrel and respectively connected between respective one ends of said high-position locating surface portions and respective one ends of said homing surface portions, a plurality of high-position stop surface portions located at the top side of said outer barrel and respectively upwardly extended from respective opposing ends of said high-position locating surface portions, a plurality of upright stop surface portions located at the top side of said outer barrel and respectively upwardly extended from respective opposing ends of said homing surface portions, and a plurality of position-limit grooves located at the top side of said outer barrel and respectively connected between said upright stop surface portions and said homing surface portions. 
     
     
         9 . The rotary fastener as claimed in  claim 8 , wherein said guide track unit further comprises a plurality of second sloping guide paths located at the bottom side of said operating cap member and respectively extended from respective one ends of said positioning surface portions and configured to fit said first sloping guide paths, a plurality of upright abutment surface portions located at the bottom side of said operating cap member for abutment against said upright stop surface portions respectively, and a plurality of abutment protrusions respectively connected between said positioning surface portions and said upright abutment surface portions for engaging said position-limit grooves respectively. 
     
     
         10 . The rotary fastener as claimed in  claim 1 , wherein said operating device further comprises a grip formed integral with the periphery of said operating cap member. 
     
     
         11 . The rotary fastener as claimed in  claim 10 , wherein said grip comprises a plurality of grooves and ribs alternatively spaced around the periphery of said operating cap member. 
     
     
         12 . The rotary fastener as claimed in  claim 10 , wherein said grip comprises at least one wing member outwardly extended the periphery of said operating cap member.